From patchwork Tue Jun 8 04:02:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Ryazanov X-Patchwork-Id: 456375 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 947B4C47082 for ; Tue, 8 Jun 2021 04:03:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73CCA6120F for ; Tue, 8 Jun 2021 04:03:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229782AbhFHEE6 (ORCPT ); Tue, 8 Jun 2021 00:04:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229455AbhFHEE6 (ORCPT ); Tue, 8 Jun 2021 00:04:58 -0400 Received: from mail-lf1-x133.google.com (mail-lf1-x133.google.com [IPv6:2a00:1450:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5DA6C061787; Mon, 7 Jun 2021 21:02:52 -0700 (PDT) Received: by mail-lf1-x133.google.com with SMTP id a1so20133781lfr.12; Mon, 07 Jun 2021 21:02:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=OHFz2XiGKzjMgGqDHw8Ln6pO4vzSXzZficuVDOKNoOo=; b=f26c1mSujkUX/ImJQ8SNUPBjZ5RnTP34UeX+xJK66/pAGejZI1PoCE/118wNiB7RFE Wd/ASO216UgvyczSNRZ+knpFOAXErUGW5UunOQla+i6ct2bOB2mF31u64LAeIibdQSOX C1ygTZl3bQSEDh7DZQRzTm5a0BCOTYhZHdL6YbvC0JKBaq951YfcekTWe8d8SqGUSymb XSia+eC+FinqIGjxMV6fJlV2R6OnNc4+9G+IrsJgFAa+CK4yWA/VUYO9ciqhk21CS2YA N0BJi7RNKKKGwfpgWZPp1Tpq6ijddtLnkDEPKB5FjtoKZOBwsXtWer//aN3ctX+H5pw/ Jdxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=OHFz2XiGKzjMgGqDHw8Ln6pO4vzSXzZficuVDOKNoOo=; b=d3VFQirgCiw3sahAkArvouIcX3n3OJOGghhFv6diJs77Cd3Pa4awAsZRoYjX4Hon8a cvLZ6XzgzX1UdMqHzAk67AXcQ/z8XoGFMPjHKOkISu7V6xBcih9asq5fLww8qyUS8xEM 4lUrz995Gd15iHgH1ZGUNp0mOLDU7u1zbOMyWytrW6vFOKwcsg5QXTI3kZatS7dQaFTp Sq5c/YRS9TyglwomGgZDc35OB37iqLl4siOsPB5ukxVnRLhfcqEvVzu8T7moESMpbeBn kIody0XbEItMKuwnj53TY1mf8FhSwhtdAhfgGwYSfiRz4joK4/p055q1hhYwFK6d7bwc JVXA== X-Gm-Message-State: AOAM533fdM77YIj2GgAcDG/VpU//tO+SkH8/1AAVo1Ytgdu7gdKTFXEn aK3qYwvt0U8HTbV6z+TLAezqQLgj3uc= X-Google-Smtp-Source: ABdhPJwQJ8edDU0q6xED+wYi1hRWxoziQkwDjPeRu6yHOo+Lc/PEErEU3MdhJoHzJxqqd2hjNtfjOQ== X-Received: by 2002:a05:6512:32a5:: with SMTP id q5mr13439043lfe.171.1623124971147; Mon, 07 Jun 2021 21:02:51 -0700 (PDT) Received: from rsa-laptop.internal.lan ([217.25.229.52]) by smtp.gmail.com with ESMTPSA id l23sm1729096lfj.26.2021.06.07.21.02.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Jun 2021 21:02:50 -0700 (PDT) From: Sergey Ryazanov To: Loic Poulain , "David S. Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, linux-wireless@vger.kernel.org Subject: [PATCH 02/10] wwan_hwsim: add debugfs management interface Date: Tue, 8 Jun 2021 07:02:33 +0300 Message-Id: <20210608040241.10658-3-ryazanov.s.a@gmail.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210608040241.10658-1-ryazanov.s.a@gmail.com> References: <20210608040241.10658-1-ryazanov.s.a@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org wwan_hwsim creates and removes simulated control ports on module loading and unloading. It would be helpful to be able to create/remove devices and ports at run-time to trigger wwan port (un-)register actions without module reloading. Some simulator objects (e.g. ports) do not have the underling device and it is not possible to fully manage the simulator via sysfs. wwan_hsim intend for developers, so implement it as a self-contained debugfs based management interface. Signed-off-by: Sergey Ryazanov --- drivers/net/wwan/wwan_hwsim.c | 186 +++++++++++++++++++++++++++++++++- 1 file changed, 184 insertions(+), 2 deletions(-) diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c index 96d25d7e5bb8..472cae544a2b 100644 --- a/drivers/net/wwan/wwan_hwsim.c +++ b/drivers/net/wwan/wwan_hwsim.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include static int wwan_hwsim_devsnum = 2; module_param_named(devices, wwan_hwsim_devsnum, int, 0444); @@ -22,6 +24,9 @@ MODULE_PARM_DESC(devices, "Number of simulated devices"); static struct class *wwan_hwsim_class; +static struct dentry *wwan_hwsim_debugfs_topdir; +static struct dentry *wwan_hwsim_debugfs_devcreate; + static DEFINE_SPINLOCK(wwan_hwsim_devs_lock); static LIST_HEAD(wwan_hwsim_devs); static unsigned int wwan_hwsim_dev_idx; @@ -30,6 +35,9 @@ struct wwan_hwsim_dev { struct list_head list; unsigned int id; struct device dev; + struct work_struct del_work; + struct dentry *debugfs_topdir; + struct dentry *debugfs_portcreate; spinlock_t ports_lock; /* Serialize ports creation/deletion */ unsigned int port_idx; struct list_head ports; @@ -40,6 +48,8 @@ struct wwan_hwsim_port { unsigned int id; struct wwan_hwsim_dev *dev; struct wwan_port *wwan; + struct work_struct del_work; + struct dentry *debugfs_topdir; enum { /* AT command parser state */ AT_PARSER_WAIT_A, AT_PARSER_WAIT_T, @@ -48,6 +58,12 @@ struct wwan_hwsim_port { } pstate; }; +static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops; +static const struct file_operations wwan_hwsim_debugfs_portcreate_fops; +static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops; +static void wwan_hwsim_port_del_work(struct work_struct *work); +static void wwan_hwsim_dev_del_work(struct work_struct *work); + static int wwan_hwsim_port_start(struct wwan_port *wport) { struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport); @@ -139,6 +155,7 @@ static const struct wwan_port_ops wwan_hwsim_port_ops = { static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev) { struct wwan_hwsim_port *port; + char name[0x10]; int err; port = kzalloc(sizeof(*port), GFP_KERNEL); @@ -159,6 +176,13 @@ static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev) goto err_free_port; } + INIT_WORK(&port->del_work, wwan_hwsim_port_del_work); + + snprintf(name, sizeof(name), "port%u", port->id); + port->debugfs_topdir = debugfs_create_dir(name, dev->debugfs_topdir); + debugfs_create_file("destroy", 0200, port->debugfs_topdir, port, + &wwan_hwsim_debugfs_portdestroy_fops); + return port; err_free_port: @@ -169,10 +193,34 @@ static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev) static void wwan_hwsim_port_del(struct wwan_hwsim_port *port) { + debugfs_remove(port->debugfs_topdir); + + /* Make sure that there is no pending deletion work */ + if (current_work() != &port->del_work) + cancel_work_sync(&port->del_work); + wwan_remove_port(port->wwan); kfree(port); } +static void wwan_hwsim_port_del_work(struct work_struct *work) +{ + struct wwan_hwsim_port *port = + container_of(work, typeof(*port), del_work); + struct wwan_hwsim_dev *dev = port->dev; + + spin_lock(&dev->ports_lock); + if (list_empty(&port->list)) { + /* Someone else deleting port at the moment */ + spin_unlock(&dev->ports_lock); + return; + } + list_del_init(&port->list); + spin_unlock(&dev->ports_lock); + + wwan_hwsim_port_del(port); +} + static void wwan_hwsim_dev_release(struct device *sysdev) { struct wwan_hwsim_dev *dev = container_of(sysdev, typeof(*dev), dev); @@ -204,6 +252,17 @@ static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void) if (err) goto err_free_dev; + INIT_WORK(&dev->del_work, wwan_hwsim_dev_del_work); + + dev->debugfs_topdir = debugfs_create_dir(dev_name(&dev->dev), + wwan_hwsim_debugfs_topdir); + debugfs_create_file("destroy", 0200, dev->debugfs_topdir, dev, + &wwan_hwsim_debugfs_devdestroy_fops); + dev->debugfs_portcreate = + debugfs_create_file("portcreate", 0200, + dev->debugfs_topdir, dev, + &wwan_hwsim_debugfs_portcreate_fops); + return dev; err_free_dev: @@ -214,23 +273,136 @@ static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void) static void wwan_hwsim_dev_del(struct wwan_hwsim_dev *dev) { + debugfs_remove(dev->debugfs_portcreate); /* Avoid new ports */ + spin_lock(&dev->ports_lock); while (!list_empty(&dev->ports)) { struct wwan_hwsim_port *port; port = list_first_entry(&dev->ports, struct wwan_hwsim_port, list); - list_del(&port->list); + list_del_init(&port->list); spin_unlock(&dev->ports_lock); wwan_hwsim_port_del(port); spin_lock(&dev->ports_lock); } spin_unlock(&dev->ports_lock); + debugfs_remove(dev->debugfs_topdir); + + /* Make sure that there is no pending deletion work */ + if (current_work() != &dev->del_work) + cancel_work_sync(&dev->del_work); + device_unregister(&dev->dev); /* Memory will be freed in the device release callback */ } +static void wwan_hwsim_dev_del_work(struct work_struct *work) +{ + struct wwan_hwsim_dev *dev = container_of(work, typeof(*dev), del_work); + + spin_lock(&wwan_hwsim_devs_lock); + if (list_empty(&dev->list)) { + /* Someone else deleting device at the moment */ + spin_unlock(&wwan_hwsim_devs_lock); + return; + } + list_del_init(&dev->list); + spin_unlock(&wwan_hwsim_devs_lock); + + wwan_hwsim_dev_del(dev); +} + +static ssize_t wwan_hwsim_debugfs_portdestroy_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_port *port = file->private_data; + + /* We can not delete port here since it will cause a deadlock due to + * waiting this callback to finish in the debugfs_remove() call. So, + * use workqueue. + */ + schedule_work(&port->del_work); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops = { + .write = wwan_hwsim_debugfs_portdestroy_write, + .open = simple_open, + .llseek = noop_llseek, +}; + +static ssize_t wwan_hwsim_debugfs_portcreate_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_dev *dev = file->private_data; + struct wwan_hwsim_port *port; + + port = wwan_hwsim_port_new(dev); + if (IS_ERR(port)) + return PTR_ERR(port); + + spin_lock(&dev->ports_lock); + list_add_tail(&port->list, &dev->ports); + spin_unlock(&dev->ports_lock); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_portcreate_fops = { + .write = wwan_hwsim_debugfs_portcreate_write, + .open = simple_open, + .llseek = noop_llseek, +}; + +static ssize_t wwan_hwsim_debugfs_devdestroy_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_dev *dev = file->private_data; + + /* We can not delete device here since it will cause a deadlock due to + * waiting this callback to finish in the debugfs_remove() call. So, + * use workqueue. + */ + schedule_work(&dev->del_work); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops = { + .write = wwan_hwsim_debugfs_devdestroy_write, + .open = simple_open, + .llseek = noop_llseek, +}; + +static ssize_t wwan_hwsim_debugfs_devcreate_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_dev *dev; + + dev = wwan_hwsim_dev_new(); + if (IS_ERR(dev)) + return PTR_ERR(dev); + + spin_lock(&wwan_hwsim_devs_lock); + list_add_tail(&dev->list, &wwan_hwsim_devs); + spin_unlock(&wwan_hwsim_devs_lock); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_devcreate_fops = { + .write = wwan_hwsim_debugfs_devcreate_write, + .open = simple_open, + .llseek = noop_llseek, +}; + static int __init wwan_hwsim_init_devs(void) { struct wwan_hwsim_dev *dev; @@ -272,7 +444,7 @@ static void wwan_hwsim_free_devs(void) while (!list_empty(&wwan_hwsim_devs)) { dev = list_first_entry(&wwan_hwsim_devs, struct wwan_hwsim_dev, list); - list_del(&dev->list); + list_del_init(&dev->list); spin_unlock(&wwan_hwsim_devs_lock); wwan_hwsim_dev_del(dev); spin_lock(&wwan_hwsim_devs_lock); @@ -291,6 +463,12 @@ static int __init wwan_hwsim_init(void) if (IS_ERR(wwan_hwsim_class)) return PTR_ERR(wwan_hwsim_class); + wwan_hwsim_debugfs_topdir = debugfs_create_dir("wwan_hwsim", NULL); + wwan_hwsim_debugfs_devcreate = + debugfs_create_file("devcreate", 0200, + wwan_hwsim_debugfs_topdir, NULL, + &wwan_hwsim_debugfs_devcreate_fops); + err = wwan_hwsim_init_devs(); if (err) goto err_clean_devs; @@ -299,6 +477,7 @@ static int __init wwan_hwsim_init(void) err_clean_devs: wwan_hwsim_free_devs(); + debugfs_remove(wwan_hwsim_debugfs_topdir); class_destroy(wwan_hwsim_class); return err; @@ -306,7 +485,10 @@ static int __init wwan_hwsim_init(void) static void __exit wwan_hwsim_exit(void) { + debugfs_remove(wwan_hwsim_debugfs_devcreate); /* Avoid new devs */ wwan_hwsim_free_devs(); + flush_scheduled_work(); /* Wait deletion works completion */ + debugfs_remove(wwan_hwsim_debugfs_topdir); class_destroy(wwan_hwsim_class); }